Our findings demonstrate that when both Thai high school and undergraduate students received a favor, they reported a feeling of appreciativeness, indebtedness and general positive feelings. Then, we investigated relationships between the three feelings of gratitude and four variables of cognition towards gratitude situation and enhancement of prosocial motivation. The results showed that the models of relationships among these variables are similar in high school and undergraduate students. In both samples, feelings of appreciativeness positively correlated to enhancement of prosocial motivation. The results